not 100% sure of exact time it stays there but the debris is there for a good amount of time
no its not possible to split the mod up this version will include far more then the origonal mod
the origonal mod was just ship files + textures and a hand full of songs / voices the up coming version will have, Ships (with fighter movement )+ stations Full sound / song / voice Debris files (wont be 100% done for the release only a handful of ships have the debris files so far i am currently working as hard + fast as i can to get more ships with the debris files but as you know quality over quantity ^^)+ textures for normal ships + stations ones Research trees all the files that go with this
the mod is currently 580mb and that is 2 factions wait for the other 3 to be added (not all stations are done yet for each the feds and klinks)
releases that follow the first entrenchment release will add more to the mod (factions ships / stations etc etc etc) the mod could end up being 2gig lol ! but it will be well worth it